It’s well-known that obesity can cause or exacerbate osteoarthritis (OA) through excessive mechanical loading. But another mechanism through which obesity can affect joint health is via inflammation and we now know that our gut microbes play a crucial role.

Recent research by Schott et al. has looked into the link between obesity, gut microbes and OA. They found a difference between the types of gut bacteria in obese mice compared to lean mice. The obese mice had more pro-inflammatory and fewer anti-inflammatory species than lean mice. The imbalance led to accelerated knee OA due to systemic inflammation and macrophage migration to the synovium. Interestingly, they found that oligofructose, a non-digestible prebiotic fibre, can help restore a normal lean gut microbiota in obese mice. The restoration of lean gut microbes was “associated with reduced inflammation in the colon, circulation and knee and protection from OA”.

Obviously one could wonder whether these findings apply to humans. About a year ago Dai et al. published the results of long-term studies on around 6000 people. Their findings consistently showed that higher total fibre intake was related to a lower risk of getting symptoms of knee OA!

Hoffman et al., from Marquette University in Wisconsin, have recently studied the effects of artificial sweeteners on rat physiology. They found that the consumption of aspartame (E951) or acesulfame potassium (E950) can lead to vascular impairment and changes in fat metabolism “that may be important during the onset and progression of diabetes and obesity”.